Thermostatic throttle stop



F 11, 1947 1.. E. PERRINE 2,415,529

THERMOSTATIC THROTTLE STOP File'd Oct. 24, 1940 v 2 Sheets-Sheet l (lttomegs Feb, 11, 1947. L. 1;. PERRINE 2,415,529

THERMOSTATIC THROTTLE STOP Filed Oct. 24, 1940 2 Sheets-Sheet 2 attornegs fiatenteci Feb. 11, 1947 TED STATES PATENT THERMOEzTATIC THROTTLE, STOP Lester E. Perrine, Detroit, Mich, assignor to Gen eral Motors Corporation, Detroit, Mich, a corporation of Delaware Application October 24, 1940, Serial No. 362,511

11 Claims. (Cl. 123-119) 1 2 When an automotive vehicle is brought to a In the accompanying drawings: temporary stop, as it is quite frequently, particu- Figure 1 shows a portion of an automotive velarly in city driving, it is, of course, desirable to hicle on whose propelling engine there is pro keep its propelling enginge running idly at the Vided a stopin accordance with my invention to minimum speed at which it will operate without limit the extent to which the throttle valve of the danger of stalling. To prevent the throttle valve carburetor may be closed;

of the carburetor of the engine being closed so Figure 2 is an enlarged view of the carburetor far that the rate at which the carburetor supand associated parts of the engine shown in Figplies combustible mixture to the engine is reure 1 as they appear when viewed from the engine I duced to such a low value that the engine cannot n side;

continue to operate on it even idly, it became Figure 3 is a still further enlarged view, mainly general practice, long before the applicant made in top pla of the Operating mechanism for the his invention, to provide a stop to limit the eX- choke valve and the stop for the throttle valve tent to which the throttle valve could be closed. of the carburetor shown in the P eceding figures;

However, since, with the throttle valve'opened Figure 4 is a perspective view of the stop for t given t t an engine i l idl faster when the throttle valve of the carburetor shown in the it is warmed up than when it is cold and, to keep preceding ure an engine running idly without danger of stalling, n t e drawings the reference character Hl inthe throttle valve must be opened farther when dicates the internal combustion propelling en ine the engine is cold than when it is warmed up, and the reference character It the floor board of th tops i use before th applicant made i the drivers compartment of an automotive veinvention were far from satisfactory. If they hiele- Within the driVerS o pa ent of the w adjusted t give t engine t desired idle vehicle, there are located the usual controls which sp ed when it was warmed up, the engine would include a starter pedal I2 mounted so that it can stall if the throttle valve were closed as far as reek in bearings an accelerator pe al 4 possible when it was cold; and if they were admounted so that it a ing on a ball-headed justed to give the engine the desired idle speed d and a throttle c r l lever is at the when it was cold, the engine would race with the ppe e d of t e t i co umn ll. throttle valve closed as far as possible when it engine is equipped with a c rburetor was warmed up. Before the applicant made his which includes y 59 Which s mounted invention, it was the general practice to adjust on the intake man-field m of the ethe stop so as to give the engine the desired idle Through the body is eXtends a duct 2! t rou h Speed when it was warmed up and to leave it to whose upper end air enters the carburetor and the operator of the vehicle to keep the throttle from Whose lower end combustible ixture of valve opened sufficiently beyond this position fuel and air is discharged into the intake manl the engine wa wa rmed up But this, f The portion of the intake manifold. course, was not a atisfa tory Solution f the into which the combustible mixture enters from problem, the carburetor is surrounded by a jacket This invention has to do with internal combusthrough which exhaust gases from the e i e t engines of t type used to propel automo may be circulated to heat the combustible mixtive vehicles and for its principal object to pro- In the upper end of the t there is vide a stop o limit the extent to which the located a choke valve 23 by which the entrance throttle valve of the carburetor of the engine may of air into the Carburetor thus, the Tiehbe closed which is automatically adjustable upon ness of the combustible mixture supplied by the changes in temperature of the engine so that the carburetor to the cylinders of the engine is regextent to which the throttle valve may be closed meted e choke Valve is Controlled mechvaries directly and the idle speed of the engine amsm earned by 3 body 23 which is mounted inversely with the temperature of the engine and on the make mamfold at one Side of the has the desired value at all temperatures carburetor. This mechanism is illustrated and For better understanding of the at and described in detail in my application Serial No. objects of this invention, reference is made to 613,225, filed J1me f Which s hthe following specification in which there is deplieation is, n part, a Continuation, and in y scribed the preferred embodiment of the inven- Patent No. 2,226,580, dated December 31, 19%, tion which is illustrated in the accompanying which is also, in part, a continuation of my apdrawings. 7 a 5 plication Serial No. 618,225.

In the lower end of the duct 21, there is located a throttle valve 25 of the butterfly type by which the rate at which combustible mixture is supplied by the carburetor 8 to the cylinders and thus the speed of the engine is regulated. The throttle valve 25 is mounted on a shaft 25 which is journaled in the body of the carburetor and to which is secured an operating lever 21. The lever 27 is connected by a link 28 to one arm 29 of a two-armed lever 29- which is fixed on one end of a shaft 3i. On the other end of the shaft 3| which extends across the engine and is journaled in brackets 32 which are mounted on the top of the engine, there is fixed a lever 33.

The mechanism by which the lever 33 and through it the throttle valve 25 is connected to the starter pedal 12, the accelerator pedal i l and the throttle control lever It is like the corresponding mechanism disclosed in the Dykstra and Wauters Patent No. 2,082,538. It includes a link 34 which connects the lever, 33 to one arm 35 of a two-armed lever 35Ei3t which is mounted so that it can rock on a pin 3'5 which projects from the side of the engine iii. A coil spring 38 which encircles the pin 3'! tends to rotate the lever 35-35 clockwise and move the throttle valve 25 toward its closed position.

The accelerator pedal it is connected to the arm 36 of the two-armed lever 35-35 by a link 39 so that when the accelerator pedal is depressed the throttle valve 25 will be moved toward its opened position and when the: accelerator pedal is released the spring 38 will move the throttle valve toward its closed position and the accelerator pedalback toward its original position.

The throttle control lever i6 is fixed to the upper end of a hollow shaft 49 which extends through the steering column ll. On the lower end of the hollow shaft ii} there is fixed a lever ll whose outer end is connected by a link 5?. to one arm 43 of a two-armed lever 43 id which is mounted so that it can rock on the pin 3']. On the lever iii-l4 there is formed a lug 45 which engages a lug Q6 on the lever 35-35 when the lever 43i i is rotated counterclockwise. Consequently, when the throttle control lever I5 is moved in the corresponding direction the lever -3l l moves the lever 3535 counterclockwise and the throttle valve 25 toward its open position. There is, however, so much friction in the bearings in which the hollow shaft 40 is journaled that the spring 38 will not move the 'throttle valve back toward its closed position until the throttle control lever has been moved to the corresponding position.

To put into operation, when the starter pedal i2 is depressed, the motor ll by which the engine i9 is cranked to start it, there is connected to the starter pedal by a link 58 the outer end of a lever 49. The starter pedal is also connected by a link 59 to one arm 5! of a two-armed lever 5l52 which is mounted so that it can rock on the pin 3?. The arm 52 of the lever 51-52 extends to a point opposite a finger 53 on the lever 3535 and on the arm 5! of the lever t l-52 opposite an adjusting screw 54 which extends through the arm id of the lever d34l there is formed an ear 55. The result is that when the starter pedal is depressed to start the engine, the arm 52 of the lever 5l-52 engages the finger 53 and moves the lever 35-35 counterclockwise and the throttle valve 25 toward its opened position sufiiciently to insure a quick and easy start of the engine and the ear 55 engages the adjusting screw 54 and moves the. lever.

4344 and the throttle control lever is to a lesser extent in the corresponding direction. When the starter pedal is released after the engine has started a spring which is not shown in the drawings moves it back to its original position and the spring 38 moves the throttle valve back toward its closed position until the lug 45 engages thelug 45.

To limit movement of the throttle valve 25 toward its closed position there is provided a sleeve 55 with a cam 57 on it which is mounted so that it can rotate on a pin 58 which projects from the side of the body 24 of the choke valve controlling mechanism which faces the engine. On the outer end of the sleeve 55 there is formed a cylindrical housing 59 in which there is located a bimetallic coil spring thermostat 6! whose ends are fixed, respectively, to the housing 59 and the outer end of the pin 58.

On the end of a shaft 5! which is mounted so that it can rock in the body 24 of the choke valve controlling mechanism and projects from the same side oiit as the pin 58 between the pin 58 and the shaft 3| there is fixed a two-armed lever (iii-63. One arm 63 of the two-armed lever 6253 extends generally in the direction of and terminates above and somewhat beyond the pin 52 and through it opposite the cam 51 there extends an adjusting screw 64. The other arm 52 of the lever 6263 extends generally in the direction of the shaft 3! and on it there is formed an ear 65. On the same end of the shaft 5! as the lever 62-453 there is mounted so that it can rock on it a lever 65 which extendsdn the same general direction as the arm 62 or" the lever 5263 and underlies the ear 65 which is formed on it. The outer end of the lever 66 is connected by a link 67 to the arm 36 of the two-armed lever 29.3l which is fixed on the shaft 3! A spring 6.8. whose ends are connected, respectively, to the arm 63 of the two-armed lever 62-63 and the body 24 of the choke valve controlling mechanism tends to rotate the lever 62-453 counterclockwise and maintain the ear 65 in contact with the lever 66 and move the screw 6 away from the cam 51. I

The exhaust manifold of the engine l9 which in the interest of clarity in the illustration of my invention has not been shown in Figure 2 but is indicated by the reference character 69 in Figure 3; extends generally parallel to and above the intake manifold 20. Consequently, when it is positioned as it has been described, the thermostat B0 is, as Figure 3 indicates, located close to and will be quickly affected by changes in the temperature of the exhaust manifold 69.

When the throttle valve 25 is moved toward its closed position the lever 66 engages the ear B5 on the arm, 62 of the two-armed lever 62-63 and rotates the latter clockwise until the. screw 64 engages the cam 5.? which positively prevents further movement of the throttle valve toward its closedv position. The thermostat. 68 is so constructed and arranged that as its temperature rises it tends to rotate the cam 57 to a position in which the adjusting screw $4 is opposite the portion of the cam nearest the axis of the sleeve 56 and that as its temperature falls it tends to rotate the cam. to a. position in which the adjusting screw is opposite the portion of the cam farthe engine It inversely with the'temperature of the engine. The cam 51 will, of course, beso shaped and the thermostat 60 so calibrated that at no temperature can the throttle valve be closed to such an extent as to prevent the carburetor i8 supplying to the cylinders of the engine combustible mixture at the rate necessary to insure operation of the engine Without danger of stalling at that temperatureand that at no temperature will the carburetor supply to the cylinders of the engine when the adjusting screw 64 is in contact with the cam 51 combustible mixture at a rate in excess of that necessary to insure operation of the engine without danger of stalling at that temperature.

The thermostat 60 is not made suiiiciently poweriul to rotate the cam 51 while the adjusting screw 65 is held in contact with the cam by the throttle valve closing spring 38. This because of the cost and space required by a sufiiciently powerful thermostat.

Because the thermostat til is so weak it is necessary that the throttle valve 25 be opened sufficiently to permit the spring 68 to move the adjusting screw 6% out of contact with the cam E? before the thermostat can rotate the cam. The throttle valve is opened to this extent in normal driving and the thermostat thus given an opportunity to make the proper adjustment of the cam as the engine warms up. The interconnection between the starter pedal I2 and the throttle valve which is illustrated in the drawings and has been described also opens the throttle valve to this extent when the starter pedal is depressed to start the engine and the thermostat is thus given an opportunity to make the proper adjustment of the cam when the engine is started. Thus, without any conscious efiort on the part of the operator, the thermostat E30 is given an opportunity to make the proper adjustment of the cam 5'! when the engine is started after it has been stopped as well as it warms up after it has been started.

While, since in the form illustrated in the drawing the thermostat 68 is not sufficiently powerful to rotate the cam 51 while the adjusting screw B l is held in contact with the cam by the throttle valve closing spring 38, it is necessary to employ other means to open the throttle valve to the extent necessary to insure a quick and easy start of the engine it and give the thermostat an opportunity to make the proper adjustment of the cam, it is, of course, possible to make the thermostat sufficiently powerful to rotate the cam while the adjusting screw is held in contact with the cam by the throttle valve closing spring and thus make it unnecessary to employ other means to open the throttle valve to the extent necessary to insure a quick and easy start of the engine or give the thermostat an opportunity to make the proper adjustment of the cam.

I claim:

1. In a carburetor having a riser heated by the exhaust of the engine with which the carburetor is associated, a throttle valve controlling the flow of combustible mixture from the carburetor, an idling control arm limiting the closing movement of said throttle valve to determine the idling speed of the engine, a cam member providing an abutment for said arm determining the idling position of said throttle valve, and a bimetallic strip engaging said cam member and operating in accordance with the temperature of the engine to rotate said cam to various positions in a manner increasing the idling speed of the engine when the same is cold.

2. In an internal combustion engine, a carburetor, means for regulating the speed of the engine including a valve which controls the passage of combustible mixture from the carburetor to the engine and means for moving the valve, means for determining the idle speed of the engine including a rotatably mounted cam so arranged that an element which is movable with the valve moves into and out of engagement with it when the valve is moved toward and awa from its closed position and it opposes further movement of the valve toward its closed position after the element engages it, and a thermostat which tends to position the cam so that it is engaged by the element earlier in the course of the movement of the valve toward its closed position when the engine is cold than when it is hot and thus to adjust the idle speed of the engine so that it is greater when the engine is cold than when it is hot.

3. In an internal combustion engine, a carburetor, means for regulating the speed of the engine including a valve which controls the passage of combustible mixture from the carburetor to the engine and means for moving the valve, means for determining the idle speed of the engine including a member so arranged that an element which is movable with the valve moves into and out of engagement with it when the valve is moved toward and away from its closed position when the engine is cold and it unyieldingly blocks further movement of the valve toward its closed position after the element engages it, and a thermostat which tends to position the first mentioned member so that the third mentioned means is engaged by the element earlier in the course of the movement of the valve toward its closed position when the engine is cold than when it is hot and thus to adjust the idle speed of the engine so that it is greater when the engine is cold than when it is hot.

4. In an internal combustion engine, a carburetor, means for regulating the speed of the engine including a valve which controls the passage of combustible mixture from the carburetor to the engine and by whose movement changes in the speed-of the engine are initiated, and means for determining the idle speed of the engine and adjusting it so that it is greater when the engine is cold than when it is hot including a temperature controlled member so arranged that it may move from a position in which it unyieldingly opposes movement of the valve to its normal idling position when the engine is cold and to a position in which it does not interfere with movement of the valve to its normal idling position when the temperature of the engine rises.

5. In an internal combustion engine, a carburetor, means for regulating the speed of the engine including a valve which controls the passage of combustible mixture from the carburetor to the engine and means for moving the valve, means for determining the idle speed of the engine including an element so arranged that an element which is movable with the valve moves into and out of engagement with it when the valve is moved toward and away from its closed position when the engine i cold and it unyieldingly blocks further movement of the valve toward its closed position after the second mentioned element engages it, and a thermostat which tends to position one of the mentioned elements so that the third mentioned means is engaged by an element which is movable with the valve earlier in the course of the movement of the valve toward its closed position when the engine is cold than when it is hot and thus to adjust the idle speed .of the engine so that it is greater when .the engine is cold than when it is hot.

6. In an internal combustion engine, a carburetor which includes a valve for regulating admission .of air into the carburetor and means for actuating the valve, means for regulating the speed of the engine, including a valve which control the passage of combustible mixture from the carburetor to the engine and by whose movement changes in speed of the engine are initiated, and means independent of that for actuating the first mentioned valve for determining the idle speed of the engine and adjusting it so that it is greater when the engine is cold than when it is hot including a temperature controlled member so arranged that it does not interfere with movement of the second mentioned valve toward its opened position and may move from a position in which it opposes when the engine is cold to a position in which it does not oppose when the engine is hot movement of the second mentioned valve to its normal idling position.

7. In an internal combustion engine, a carburetor, means for regulating the speed of the engine including a valve which controls the passage of combustible mixture from the carburetor to the engine and by whose movement changes in speed of the engine areinitiated, and means for determining the idle speed of the engine and adjusting it so that it is greater when the engine is cold than when it is hot including a temperature controlled member whose movement is affected by a single engine operating attribute only, namely, temperature, so arranged that it does not interfere with movement of the valve toward its opened position and may move from a position in which it opposes when the engine is cold to a position in which it does not oppose when the engine is hot movement of the valve to its normal idling position.

8. A control mechanism for an internal combustion engine carburetor having a throttle, comprising a haft, a thermostat element fixed to the shaft, a rotatable stop member floating on the shaft, means connecting the thermostat to the stop member to rotate the same proportionally to temperature, and means associated with the throttle and engaging the stop member to prevent closing the throttle.

9. In a carburetor having a main induction passage, a throttle shaft rotatably mounted in the induction passage, a throttle valve fixed to the throttle shaft and controlling the outlet of the induction passage, an adjustable stop member connected to the throttle shaft, manual means to actuate the throttle valve, a rotatable member adapted to coact with the stop member to limit the closing movement of the throttle valve, and thermostatic means to vary the relation between the rotatable member and the stop member in accordance with temperature.

10. A control mechanism for an internal combus'tion engine carburetor having a throttle adapted to control the now of fuel mixture to the engine, manual means to actuate the throttle, means to prevent the throttle from completely closing comprising a thermostat, a cam rotated by said thermostat independently of said manual means, an arm connectedto said throttle, and adjustable means on the arm engaging the cam to limit the closing movement of the throttle in a degree inversely proportional to the temperature.

. 11. Control mechanism for an internal combustion engine carburetor having a throttle, co l-- .prising a shaft, a stop member oscillatably float- REFERENCES CETED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,799,792 Hoepner Apr. 7, 1931 1,785,787 Rayfield Dec. 23, 1930 2,127,735 Hunt Aug. 23, 1938 2,142,503 Ericsson Jan. 3, 1939 1,858,454 Lund May 17, 1932 2,867,079 Wooley Jan. 5, 1937 2,138,853 Gitzendanner Dec. 6, 1938 2,211,221 Wilkerson Aug. 13, 1940 2,099,131 Edele July 23, 1935 2,082,538 Dykstra et a1 "June 1, 1937 682,526 Brooke Sept. 10, 1901 2,110,884 Leonard Mar. 15, 1938 FOREIGN PATENTS Number Country Date 363,278 Birka. (British) Dec. 17, 1931 

